PHP 数据收集 - 使用 class 构造将数字键替换为字符串标识

Question

我正在试验数据收集对象，想使用 class 构造来更改传递给新实例化对象的数组的数组键。

主要思想是可以使用数字键传递数组，然后每个数字键将被替换为字符串值。该系统基于这样一个事实，即数组将只有一个数组数组，每个数组包含三个 key/value 对。（见数据示例）。我知道这很脆弱，我打算接下来解决这个问题。

Class:

class newsCollection {

    private $collection;

    public function __construct($data)
    {
        foreach ($data[0] as $key => $value) {

            switch ($key) {
                case 0:
                    // Replace key ID with a string ie. 0 with "headline"
                    break;
                case 1:
                    // Replace key ID with a string ie. 1 with "date"
                    break;
                case 2:
                    // Replace key ID with a string ie. 2 with "author"
                    break;
            }
        }

        $this->collection = $data;
    }

    public function getNewsCollection()
    {
        return $this->collection;
    }
}

数据（数组）：

$sports = [
    [
        "Boston Red Sox vs New York Yankees - 9-3",
        "19.06.2017",
        "ESPN"
    ],
    [
       "Boston Patriot QB breaks new record!",
       "16.07.2017",
       "NESN"
    ],
    [
        "Celtics coach John Doe inducted into hall of fame",
        "25.07.2017",
        "Fox Sports"
    ],
    [
        "Boston Brewins win 16-5 against New York's Rangers",
        "21.08.2017",
        "NESN"
    ]
];

期望结果示例：

$sports = [
    [
        "headline" => Boston Red Sox vs New York Yankees - 9-3",
        "date => "19.06.2017",
        "author" => "ESPN"
    ],
    ect..
];

Answer 1

只需创建临时数组并将其分配给集合即可。将您的 constructor 更改为 :

public function __construct($data)
    {
      $new_data = array();
        foreach ($data as $key => $value) {
           if(is_array($value))
           {
              $new_data_tmp["headline"] = isset($value[0])?$value[0]:"";
              $new_data_tmp["date"] = isset($value[1])?$value[1]:"";
              $new_data_tmp["author"] = isset($value[2])?$value[2]:"";
              $new_data[] = $new_data_tmp;
           }
        }

        $this->collection = $new_data;
    }

Answer 2

您可以用您想要的按键制作一个array，然后使用array_combine()将它们设置为您输入array的按键。像这样：

private $keys = [
    "headline",
    "date",
    "author",
];

// ...

public function __construct($data)
{
    foreach ($data as &$el) {
        $el = array_combine($this->keys, $el);
    }

    $this->collection = $data;
}

注意它是通过引用完成的，所以我们正在修改 foreach 循环中的实际元素。你也应该根据自己的需要做一些验证。

作为旁注，您应该 not do any work in the constructor。它会给你带来麻烦。最好让另一个函数对您的输入值进行初始工作：

<?php
class newsCollection {

    private $collection;
    private $keys = [
        "headline",
        "date",
        "author",
    ];

    public function __construct($data)
    {
        $this->collection = $data;
    }

    public function assingKeys() {
        foreach ($this->collection as &$el) {
            $el = array_combine($this->keys, $el);
        }
    }

    public function getNewsCollection()
    {
        return $this->collection;
    }
}

$c = new newsCollection($sports);
$c->assignKeys();
$collection = $c->getNewsCollection();

Demo

PHP 数据收集 - 使用 class 构造将数字键替换为字符串标识

PHP data collection - use class construct to replace numerical key with string ident

php

arrays

class

object

key-value